


a fleeting illness

by FairyRose95



Category: BanG Dream! Girl's Band Party! (Video Game)
Genre: Angst with a Happy Ending, F/F, Hanahaki Disease, Love Confessions, Mutual Pining, Rare Pairings
Language: English
Status: Completed
Published: 2019-07-04
Updated: 2019-07-07
Packaged: 2020-06-07 19:02:39
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 3
Words: 3,657
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19475386
Author URL: https://archiveofourown.org/users/FairyRose95/pseuds/FairyRose95
Summary: Udagawa Tomoe had the most popular girl in school head over heels for her.And she was none the wiser.





	1. Chapter 1

Kaoru had been feeling a little under the weather as of recent.   
  
Maybe she had caught a cold as it was nearing winter and these days were colder than most. Maybe she was outside too long with Hello Happy, or maybe she didn't fully dry her hair last night. She wasn't sure in the slightest.   
  
She dragged her feet down the corridors of Haneoka, greeting all the little kittens with as much enthusiasm as she could muster. She hadn't the slightest clue why she was feeling the way she was though.   
  
But that persistent bug at the bottom of her throat would not go _away_ , no matter how much she cleared her throat.   
  
She swallowed and continued on until it was the second to last class of the day. Kaoru scribbled down the notes, half-way listening to the teacher as she swallowed deeply to get the scratchiness to die down.   
  
It wasn't until she walked out of class that the itching got _worse_.   
  
Because there along the halls stood one of the most magnificent creatures her eyes had ever settled upon. Now, she hardly lets her dwell on these dwindling feelings swirling in her gut, but sometimes she could not help _but_.   
  
The object of her affection was near the stairwell, close to the first years hall, with her small group of friends she was always around. She stood a head taller than all of the girls, and even was her rival prince within these halls.   
  
Brilliant red hair nestled atop olive skin, cerulean eyes that always _always_ were piercing, gentle yet sharp features...  
  
And a kindness and modesty that very much battled with her passionate appearance. Yes, the girl can be passionate, especially when her friends were in danger or she was behind her trusted drums, but she never, _ever_ , spoke a mean word. The warmth and kindness nestled in those eyes did not surprise Kaoru in the slightest that the girls gravitated towards her. Honestly, Udagawa Tomoe had the most popular girl in school head over heels for her.   
  
And she was none the wiser.   
  
As she stared at her affection, the girls surrounding Kaoru becoming concerned and annoyed by their prince's lack of response, the guitarist began to feel that tickle in her throat turn into something _sharp_ and _pointy_. And as she tried to clear her throat, watching Tomoe laugh with her friends began to make the sharpness rise upwards and upwards until it was to the point she couldn't hold the cough in any longer.  
  
With a quick adieu she shuffled for the bathroom, hoping and praying she would make it on time, and right as she neared the stall she closed the door, locked, and _coughed_.  
  
And coughed, and coughed, and coughed. Coughed until that... _thing_... was out of her body and into the toilet.   
  
Gracious, it felt like something soft was in her mouth, and as she spit it out she couldn't help but to open one red eye and slowly both eyes widened.   
  
Because in that toilet bowl was not what she was expecting in the _slightest_. She had to rub her eyes to confirm she wasn't hallucinating.  
  
But, no, it very much was there.  
  
A small twig... and nestled on top a brilliant scarlet petal.  
  
"...Ah."  
  
...This wasn't very fleeting, now was it?

**Notes for the Chapter:**

> KaoTomo is OTP and underappreciated and you can't change my mind.
> 
> Rare pair week is done but I'm still gonna write about these two awkward lesbian princes.
> 
> I've always loved the Hanahaki Disease fics. They're always fantastic and well written, so I wrote one for my best Bandori girls.
> 
> Dunno when the rest will be out, but it will, do not fret.
> 
> I love these two so much so don't be surprised if my fics are KaoTomo centric 🤷🏻♀️


	2. Chapter 2

**Summary for the Chapter:**

> "She could spare the hearts of many in exchange of her own.
> 
> She can sacrifice her love for Udagawa Tomoe, for all those that loved her.
> 
> That would be the right choice, would it not?"

4 days, 15 hours, 27 minutes.

That is how long Seta Kaoru has been plagued with this... illness.

Everyday it became increasingly unpleasant, increasingly problematic...

But she shan't let it affect her.

She has her kittens that rely on her, does she not? How can she remedy this persistent ailment without breaking the hearts of all of the kittens that she adored?

Of all the kittens that adored _her?_ The Prince of Haneoka. _Their_ Prince.

And if she did what she could to remedy this... then that would mean they would no longer have their Prince. 

That Prince would be taken by another.

She of course did her homework on this ailment that had befallen her. And what irony would have it she coughed up _two_ scarlet petals upon reading the words dancing across her screen on that dreadful night.

_Hanahaki Disease._

A disease that befalls those plagued with unrequited love. Such a dreadful ailment, and she the Prince of Haneoka were one of those with that illness.

Not very fleeting, she must say.

And not very good outcomes if she did not succumb to remedying the situation.

If she did not confess her undying love to the one that took her beating heart, she could very well suffocate on the petals that were growing in her lungs this very second.

Or she could get surgery to remove those scarlet petals, and in doing so remove the feelings of endearment that accompanied it.

She could spare the hearts of many in exchange of her own.

She can sacrifice her love for Udagawa Tomoe, for all those that loved her.

That would be the right choice, would it not?

But as she stood outside the clinic, she couldn't make herself take those vital steps to rid herself of this ailment.

**_Thump, thump, thump, thump_ **

Every beat of her heart beated for the drummer. Like the steady sound of the Taiko drums a block away.

How fitting and ironic it was that the clinic was so close to where her beloved practiced on those drums, and how fitting it was that that fiery priestess beat the drums along with the beat of her own heart.

Her heart that beat for Tomoe and Tomoe only.

She can't do this surgery. Doing this surgery will rid her of all the feelings for the beautiful drummer, and she just couldn't make herself do that. 

So it was either break the hearts of all her kittens by professing her love to the other Prince of Haneoka.

Or break the hearts of all her kittens by suffocating on scarlet red petals that grew for the other Prince of Haneoka.

She was in quite the predicament.

The urge to cough began to rise once more, the urge becoming more and more persistent, and in the middle of the sidewalk she tried to covertly cough up those scarlet petals that were increasing by the dozen.

"Now this is what I call irony at its finest."

Kaoru turned to see a head of blonde hair and a smile that had been perfected too many times for the sake of the cameras.

Kaoru swallowed down the rest of the petals, the bitter taste of pollen engulfing her mouth, but she placed the petals that escaped her mouth inside of her pocket before turning fully, "Ah if it isn't one of my dearest kittens, Chisato. Whatever are you doing at this time of day, my dear? Taking a brisk walk around town? Ah, how fleeting~"

Even she could tell the emptiness behind those words, and she knew her friend, one that has known her the longest, could see it too. The bags under the eyes, the hollowness in the tone...

The breaking of her heart.

One manicured eyebrow raised before nodding her head forward, "Let's take a walk, ne, Kao-chan?"

Before the blush could engulf her and she could retort, the shorter girl walked past, fully expecting the other to follow.

Kaoru looked up at the building and back towards her childhood friend. She followed the latter.

"So," A few raindrops fell. Chisato opened her umbrella and held it over to Kaoru. The tallest of the two grabbed the umbrella and held it over head as the rain began to come down more. "How long?"

She could either play it off, feign ignorance to the matter at hand, but Kaoru knew as well as Chisato that the lie would be amateur at its finest.

So to spare Kaoru any more embarrassment, and Chisato any more irritance, Kaoru answered, "About 5 days now."

"Hm." The steady beat of the rain accompanied the beat of her heart and the beat of the drums. Chisato ignored it all, "And who is it, if I may ask? Surely it isn't me."

"Ah, that would be something would it not? But alas you are spared, my dear Chisato, for it isn't you." Her flowery words did little for the bassist and she just looked up expectantly for the answer that was sure to come out of her mouth, "..." Kaoru blushed, "...Tomoe-chan."

Chisato's eyebrows furrowed, "Who... oh! That drummer for Afterglow? The one with the red hair?"

A vision of Tomoe in the auditorium, arms crossed and face ignited with a blush so fierce it matched her scarlet hair, engulfed her.

_"...'Fleetingly'...? I-I mean, as long as I was able to live up to your expectations, that's cool."_

Kaoru couldn't cover the cough this time, and the umbrella dropped onto the sidewalk as the cough was so intense the guitarist had to throw her hands forwards to catch herself lest she fall face first.

Rain pelted onto her back as she coughed up those red petals, the irony coming back full force as she began to recognize the flower that had plagued her lungs.

She felt a small hand on her back and the rain no long hit her back and purple hair. 

Cerulean eyes wide with surprise as Kaoru held something out to her,

_"Huh? You brought cards and roses for us too?"_

How ironic it was that the flower plaguing her lungs was so similar to the one she held out to the drummer on White Day.

Hers was a more vibrant red than the others, Kaoru made sure of.

_Because it matched the color of her hair._

"You need to tell her."

She shook her head, she can't do that she can't. Too many would be hurt, too many would have their hearts broken.

And what if one of them was plagued with this illness because of _her?_ She couldn't even think about that. And she spoke those words to Chisato. All of the worry and guilt swirling inside of her. How so many would be hurt. She can't. She _can't!_

A harsh smack made contact with her lower back and she yelped. Then blushed.

She looked up to see stern violet eyes, blonde hair plastered along her forehead from the beat of the rain. Kaoru's eyes widened just a tad, "C-Chi-chan, you're getting wet-" 

"Seta Kaoru. You are one of the biggest idiots I've ever laid my eyes on." 

Kaoru flinched.

Chisato was unrelenting.

"You would risk _death_ over your little fanbase?! Just for them, you're going to sacrifice your life and your love for another?! Really, Kao-chan?!"

"Chisato, at least put the umbrella over you-"

"See?? This is what I'm talking about. You can't for one second worry about yourself. Instead you have to worry constantly about others. It isn't healthy, Kaoru."

Kaoru looked down at the almost perfect rose on the sidewalk.

"For once, Kaoru, please I _implore_ you... worry about yourself for once. Do things for yourself without worrying how everybody else is going to react. This could _kill_ you, Kaoru, I hope you can see that."

The rain wasn't letting down.

"Can you try that? Just this once?"

"I-"

"Kaoru-senpai...?"

Both girls looked up to see the one person that Kaoru really didn't want to see.

Oh the irony indeed.

Because standing on the sidewalk, staring at her and the petals underneath, was the one whose hair matched the petals underneath.

The one she was coughing these up _for_.

Udagawa Tomoe stared with wide eyes and her umbrella slowly fell from her lax grip.

"What...?"

Why must fate be a cruel, cruel mistress?

Kaoru wanted to cry.

**Notes for the Chapter:**

> RIP Seta Kaoru, you will surely be missed. 🙏
> 
> Hopefully I did both Kaoru and Chisato justice in terms of their personalities. Let me know if they are too out of character. I tried, Bandori gods I tried! 
> 
> This is set after the White Day Musical event, so the two childhood friends are a little more close then say before the A Rose's Name In A Transient World event.
> 
> A lot more of Tomoe is in the last chapter, I promise! This really has become Kaoru-centric 🙈


	3. Chapter 3

**Summary for the Chapter:**

> "Her pride was slowly diminishing as she began to cough once more... more and more of those petals floating down out of her mouth and onto the sidewalk. 
> 
> Until one perfect rose with the vibrant color of her hair landed in between them."

"What...?"

She refused to look up. Refused to look at the person who unintentionally did this. Refused to look up because that would mean facing this situation head on... and she wasn't sure she had the courage to do that. Nor would she know what to do once she did.

What Kaoru didn't see though was the shock in those blue eyes turn quickly to worry. 

"Seta-senpai, are you okay?!"

Knees appeared in front of her and she felt a hand rest onto her shoulder. Bigger, calloused, sturdier than the delicate one on her lower back. The flowers crept up.

"Shirasagi-senpai, is she okay? What happened?"

The flowers crept up until there was nowhere it could go.

Her pride was slowly diminishing as she began to cough once more... more and more of those petals floating down out of her mouth and onto the sidewalk. 

Until one perfect rose with the vibrant color of her hair landed in between them.

Her face was almost as red as the rose underneath from utter embarrassment and shame. How could anyone love someone with flowers coming out of their lungs?

This is truly the worst.

It was silent, the thump thump of Kaoru's heart was in beat with the rain slowly drenching the three on the sidewalk.

"Seta-senpai...?"

It was too much. Too much too soon. Chisato wanted her to do this but she didn't know if she had it in her. 

But she was the Prince of Haneoka, was she not? This should be simple. 

But the thump, thump, thump in her heart spoke otherwise, and the rain continued to pour down.

"Oneechan! I've been looking for you! Mom says to hurry home, she has dinner on the table!"

Kaoru looks up once she knows Tomoe's gaze is diverted but it was a mistake. Since violet eyes were boring into her. Chisato had always been good with those poignant stares, and Kaoru could read it plain as day on her face.

_Hurry and do it, baka._

"Oh, Ako. Tell Mom I'll be there soon. Just got held up with some friends is all."

Friends, right. Kaoru's lungs began to fill more. 

It would only just be friends, huh.

Ako only seemed to notice the other two then and she gasped, "Oh! Shirasagi-senpai! Seta-senpai!" She now seemed to notice what was on the ground between her older sister and the guitarist. Ako cocked her head, "Flowers...?"

"Ah, my apologies for worrying you so, Tomoe-chan." She tried to keep her voice steady, unlike her beating heart, and she began to stand on wobbly feet, "You should head on home to your Mother. I will be alright."

"But, Seta-senpai, you just-"

"I know, and it will be alright I assure you." Vines began to grow along her heart and lungs and constrict. She knew better than to almost cave into Chisato's ploy. "It will go away soon."

_Soon._

_"Just got held up with some friends is all."_

_Friends._

_Baka._

She turned away from the three, unable to face anybody with the conflicting thoughts bouncing around in her head.

_Baka, Baka, **Baka**_

_Thump, Thump, **Thump**_

"Kao-chan...!"

But it was too late.

Kaoru was already down the street and the rose left on the ground slowly wilted with the rain.

****

10 days, 5 hours, and 54 minutes.

The ailment was worse.

Roses began to look unsettling to Kaoru with the amount of times she had coughed them up. Perfect, perfect roses with such a vibrant shade of scarlet that it reminded her all the more of the girl that had stolen her heart. 

_"Seta-senpai...?"_

_"Just got held up with some friends is all."_

_Baka._

People had begun to worry.

Her kittens could tell something was awry. Her theater club had tried all kinds of ways to make her feel better. Misaki and Kanon were especially worried, and poor Kokoro and Hagumi tried their hardest to make her smile. Chisato called and texted her everyday.

But none of it made it better.

Especially since she still saw that same head of scarlet hair everywhere she turned.

She could tell her end was soon. It took all of her energy to get up everyday, all of her energy to even _breathe_ , and that made it worse.

_Guess this is the way it's going to end, huh?_

She couldn't handle theater club anymore, staying around people for to long always made the flowers arise, so she instead took to the rooftop to look out at the scenery.

_At least I'll die looking at the sunset that looks so much like her hair. How fitting. How fleeting._

She leaned against the railing and felt the cool breeze wash through her knappy hair. She really wasn't keeping up the sacred image of the Prince of Haneoka anymore.

What an unfortunate thing, this illness.

The door to the roof opened. 

She sighed upon hearing that voice.

"Moca, I honestly don't know how you eat and sleep so much and not gain any- oh, Seta-senpai."

Kaoru slowly raised her head with a lazy wave of her hand, too much energy expended on just that alone, "Ah, Tomoe-chan."

It lacked that poise, that cadence, and Tomoe quirked her eyebrows before looking back at her friends, "Uh, can you give us a minute? It'll be quick, promise."

"Okie~!" Moca saluted and began to drag Himari back through the roof door, the bassist fighting and yelling, "Noh, Moca! It's Kaoru-senpai though-!" 

The door to the roof shut and Kaoru huffed out a laugh. Even looking this gaunt and her kittens were still there for her. Resilient little things.

Tomoe walked up and leaned against the railing beside her, back to the rail, and she looked over at the purple-haired girl. "You don't look the hottest."

Kaoru once more huffed a laugh, but in doing so began to cough and cough. _My, it hurt so much nowadays_. The thorns tearing up her throat made it hard to even swallow. 

Tomoe turned so she can face the sky with Kaoru, "So. Hanahaki, huh?"

Kaoru turned with wide eyes, "How...?" It came out rasp, hoarse, and Tomoe chuckled and winked, "I saw you a few days ago, remember? It ain't hard to figure out."

"Ah. That is true... I suppose." Kaoru looked down at her hands, wishing hers were intertwined with the goddess beside her.

Baka.

They're just friends. Nothing more, nothing less.

A hand appeared on her arm.

"Why didn't you tell me?"

That made Kaoru jerk back, blush igniting, "I-I'm sorry?"

"Look, Seta-senpai, I may not be the smartest there is, but it didn't take a rocket scientist to figure out who those roses were for." It was hard to breathe. Too hard. The thump thump thump got harder and harder and harder. "I mean, you practically ran away when I said you were my friend."

Thump thump thump.

"So, why didn't you tell me?"

She swallowed. Pain shot through her as those vines had a vice grip on her heart and her lungs. 

"Ah. Well, you see..." Tomoe watched, intently, and the blush Kaoru had came back worse than before. "I... I was afraid of hurting... everyone... I mean, I'm their prince. Surely their Prince must stay available to them. To give them some hope, or maybe take them away from reality for just a little while. If I caved in to these feelings, then they too will be hurt. I do not want to risk hurting them."

"But how do you know?"

Kaoru looked up to those blue eyes that resembled the sky around them. Tomoe continued, "How do you know they'd be hurt? Because, honestly, it would hurt them a lot more knowing you were gone then you being taken. I mean, look at Himari. Do you really think she'd hurt more with the fact you were taken, or with the fact you were gone?"

She did speak true, this brilliant goddess. 

"And what about how I feel?"

Kaoru blinked. How she felt? She knew how she felt.

Friends.

Tomoe frowned and Kaoru felt a sharp sting in the middle of her forehead. The yelp that came out of her mouth made Tomoe laugh loudly, making Kaoru blush, "T-Tomoe-chan!"

"Ah, seeing you flustered is so weird, Seta-senpai." Tomoe's laughs died down and she looked over to the older girl, "You know, after the other day it got me thinking. About us."

Kaoru swallowed. "Oh...?"

Tomoe chuckled, "It seems silly. But I honestly never gave us a thought because I just knew there was no way. I mean, you could have any girl in the school, so why me? That's why I said what I said. Not because I didn't have... feelings... for you."

Kaoru blinked. She blinked some more. "Feelings... for... me?" She then laughed, a hearty laugh that had been a long while coming. Maybe she had gone insane, she doesn't know. "Surely you jest, Tomoe-chan, for to like someone like me..."

_With how beautiful you are. It would be a waste._

Kaoru almost threw up with how fast her body was turned. She then was looking into cerulean eyes and a flushed face, "Does it look like I'm joking? Kaoru?"

_She said my name._

And so casually too. The pain began to dwindle, the vines began to disintegrate as Tomoe said those few words.

"I like you... Kaoru."

And then she couldn't hold it in anymore. She couldn't hold back the longing she has had for the longest time, pulling that other body closer and never letting go. Connecting their lips so they could stay fused forever. That thump thump thump in her heart was loud and matched Tomoe's steady beat. But this time was different. 

Tomoe squeaked, a noise completely unlike her, but the vines and the petals and the leaves within Seta Kaoru's lungs were wilting and fading away. And Kaoru could feel the tears running down her face. 

But she refused to let go, and kept the scarlet haired girl close. 

Tomoe sighed into her chapped lips and slowly they both sunk into this feeling. Kaoru didn't care if anyone saw, or what anyone cared.

For once she thought about herself and herself only.

And the girl that had captured her heart, almost killed her, and brought her back to life.

Ah, what a fleeting love story indeed~

**Notes for the Chapter:**

> And fin~!
> 
> I hope you guys can tell why I didn't use as much... flowery-ness in my writing for this chapter? It is kinda more Kaoru's spiralling self-deprecation sorta thing, so I didn't use as much "fanciness" as I did in the second chappy.
> 
> And I really just couldn't wait anymore. I had to go ahead and write this and post it. 
> 
> Plus I couldn't just leave yall on a cliff hanger. Also I had to go ahead and give KaoTomo their happy ending cause I hate seeing Kaoru suffer like this...even though it's kinda all my fault?
> 
> Anyway, I hope you enjoyed this ride. Many kudos to those who left beautiful comments, you all are amazing! There will most definitely be more KaoTomo in the future I can promise you that.
> 
> Goodbye for now!  
> Rose


End file.
